Tephra, the Greek word for ash, is used to describe any material that is ejected by a volcano into the atmosphere (pyroclasts). Tephra includes dense blocks and bombs (> 64 mm), and lighter materials such as scoria, pumice and ash (< 2 mm). As one moves away from a volcano, the tephra deposits become finer grained (smaller particles) and thinner. This is because small airborne particles hover longer and stay within the atmosphere for a greater distance from the volcano. These particles of ash …

The sediment processing laboratory is a space for preparing marine and non-marine sedimentary samples for microscopy and other analyses, which require individual components or fabric specific analysis (e.g., Mass Spectrometry, trace metals, isotope studies…). Preparation methods include separating and picking of biogenic particles, thin section dying techniques, sieving for granulometry, and creating smear slides and acetate peels.